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Broadcom Crystal HD Support For MPlayer, FFmpeg

01-01-2011, 04:50 PM

Phoronix: Broadcom Crystal HD Support For MPlayer, FFmpeg

While those using the NVIDIA binary display driver with any modern GeForce graphics processor have great accelerated video playback on the GPU right now via VDPAU, as a GPU-independent way to offload the video playback acceleration from the CPU there s Broadcom's Crystal HD adapter, which is backed by open-source Linux drivers. The Crystal HD has already been tapped by XBMC and other free software projects, but new patches are available to utilize this technology within MPlayer and FFmpeg...

Comment

Well that has been doable with a vdpau card for quite a while now (at much lower cpu usage rates). It would be interesting to see it tackle 1080p at higher bitrates with an atom (or even 720p 60fps streams) and see if it quickly saturates the PCI-e X1 bus since the Broadcom does only decoding.

Comment

why the "woah!" any reasonable logic would tell you that even an old 68000 (even a Z80) Could handle the processing needs on the right bus to feed a dedicated ASIC Video such as these CrystalHD decoders, that's the whole purpose of such a dedicated Co-Processor/ASIC etc.

Well that has been doable with a vdpau card for quite a while now (at much lower cpu usage rates). It would be interesting to see it tackle 1080p at higher bitrates with an atom (or even 720p 60fps streams) and see if it quickly saturates the PCI-e X1 bus since the Broadcom does only decoding.

! " and see if it quickly saturates the PCI-e X1 bus "

hmm why do you think it would saturate !

(unless you mean.... given some really slow ram interaction with crap chip-sets etc and the real throughput that would restrict the real bus speed too etc...)

remember that the PCIe but is rated to 250 Mega Bytes Per second for the x1 rate, the highest official Bit rate for AVC at even Hi422P, Hi444PP Is 960,000 Kilo Bits Per second for level 5.1 at 4,096?2,048@30.0 (5)

and your Far more common HD type generic leval 4.1 being only 200,000 Kilo Bits Per second

Comment

(unless you mean.... given some really slow ram interaction with crap chip-sets etc and the real throughput that would restrict the real bus speed too etc...)

remember that the PCIe but is rated to 250 Mega Bytes Per second for the x1 rate, the highest official Bit rate for AVC at even Hi422P, Hi444PP Is 960,000 Kilo Bits Per second for level 5.1 at 4,096?2,048@30.0 (5)

and your Far more common HD type generic leval 4.1 being only 200,000 Kilo Bits Per second

You seem to be forgetting that the stream after the Broadcom decodes the stream that bandwidth greatly increases as it is no longer compressed while being sent to the video device. If you were to use your worst case scenario (4,096?2,048@30.0) that decoded stream is 6.04 Gbps (754.97 MB/s) which you can see far exceeds your PCI-e 1x slot.

A typical HD (1920x1080p @ 24fps) uncompressed would be 1.19 Gbps (149.3 MB/s). Now on top of that you have the compressed stream also being fed into the Broadcom so add another ~24 MB/s on top of that bandwidth. We are now at 175 MB/s. While in theory this should be enough it is not uncommon for buses to have lower actual bandwidth then it's theoretical top limit.

This is all very different then a situation where something like vdpau is used on the graphics card where the only bus bandwidth limit you have to worry about is it being sufficient for the single compressed stream.

Comment

"You seem to be forgetting that the stream after the Broadcom decodes the stream that bandwidth greatly increases as it is no longer compressed"

correct , and as you say it would be interesting to run some real tests.... on several motherboard chip-sets and different price ranges of ram, these being key to actual data throughput as i alluded too OC